A human body communication technology exchanges signals between devices connected to a human body by using the human body having conductivity as a communication channel. A user s touch allows network communications between various kinds of portable devices, such as personal digital assistants (PDAs), portable personal computers, digital cameras, MP3 players, and cellular phones, and network communications between a user and fixed devices, such as printers, TVs, and door entry systems.
Currently, examples of a human body communication method may include a technique using a limited passband, scrambling using a unique user identification (ID), channel coding, interleaving, and spreading.
However, the human body communication methods use a passband having an intermediate frequency (fc), which is used by most of the communication systems, in order to use a limited frequency band. Therefore, the communication systems require an analog transceiver including a digital-to-analog converter, an analog-to-digital converter, an intermediate frequency converter, and the like, which increases power consumption.
Further, the current human body communication methods are inefficient due to a limited frequency band that is used to obtain a processing gain in a time domain/frequency domain spreading method because this makes it difficult to increase a data transmission rate and achieve stable data transmission and reception.